Voice-screen for transmitter-mouthpieces.



No. 887,124. PATENTE'D'MAY 12, 1908. R. H. RALSTON.

VOICE SCREEN P OR TRANSMITTER MOUTHPIEG'BS.

APPLIEATION FILED SEPT. 1, 190,6.

WITNESSES. INVENTOH 'R.H.Ra1s+ors ROBERT I-I. RALSTON, 01* DENVER,COLORADO.

VOICE-SCREEN FOR TRANSMITTER-MOUTHPIE CE S Specification of LettersPatent.

Patented May 12, 1908.

Application filed September 1, 1906. Serial No. 333,014.

To all whom it may concern:

Be it known that 1, ROBERT II.RALS'1ON, a citizen of the United Statesof America, residing at Denver, in the county of Denver and State ofColorado, have invented certain new and useful Improvements in Voice-Screens for Transmitter-Mouthpieces, of which the following is aspecification.

This invention relates to improvements in voice screens for transmittermouthieces for telephone-transmitters and 'has or its object to providea device which by completely concentrating the waves of sound toward thediaphragm, will promote audible and distinct reproduction of articulatespeech at the receiving instrument while permitting modulation of thevoice to a very low key, and which, by inclosing the mouth of thespeaker, conceals the movement of the lips and renders the voiceinaudible to persons standin near. I attain this object by the deviceiilustrated in the accompanying drawings, in the various views of whichlike parts are similarly designated and in which,

Figure 1represents a side elevation of a telephone transmitter andadjacent parts, my improved mouthpiece being shown in section, Fig. 2anunderneath view of the detached device, partly in section, Fig. 3 afront view thereof and Fig. 4, a sectional view of the device modifiedto be employed in direct connection with the transmitter.

The device as illustrated in Figs. 1, 2 and 3 is designed to be used inconnection with the mouthpiece or funnel 5 now in use on tele honetransmitters and consists of the unnel-shaped portion 6, ob long incross section, the orifice 7 of which is, by concavity of the edges ofthe opposite sides, shaped so as to conform with the contour of theportion of the human face adjacent to and surrounding the mouth. The 0posite, reduced end of the funnelshaped portion of the device terminatesin an integral, annular extension or base 8, the outer circumferentialsurface of which is threaded to cooperate with the internal thread of anannular screw-cap 9.

One of the sides of the funnel 6 is provided, in suitable proximity tothe orifice 7, with an aperture 10 for the urpose of preventingaccumulation and su sequent compression of air within the device, whenin use.

' The contrivance, as described, is applied to the telephone instrumentby inserting the mouth of the ordinary mouthpiece 5, in the circularextension of the funnel 6, after which the cap 8 is screwed in place asshown in Fig. 1 of the drawings.

To insure an air tight joint between mouthpiece 5 and the auxiliaryfunnel, and thus farther prevent escape of sound during the use of theinstrument, I have provided two washers 11 and 13 composed of rubber orother elastic substance, one of which, 11, being placed against theshoulder 12, formed at the juncture of the funnel shaped portion 6 andits annular extension 8, engages in practice, the outer edge ofmouthpiece 5, while the other, 13, is applied between the outer edge ofthe said extension and the inwardly ranging flange 14: of the screw cap9 and engages with its inner edge the circumferential surface of themouthpiece.

The modified device 16 illustrated in Fig. 4, is intended to be applieddirectly to the transmitter 15, to take the place of the regularmouthpiece 5. Its annular portion 17 at the base of the funnel encirclesthe outwardly extending rim 18 on the face of the transmitter, and aninterposed washer 19, renders the joint air tight. Afiexible stra 20secured to lugs 21 on the device, affor s means to secure thecontrivance to the transmitter.

In this connection I wish to observe that the manner of connecting thedevice to the transmitter or to its mouthpiece is ofminor importance andthat variation of form and arrangement of this portion of' thecontrivance, may be availed of within the spirit of my invention, whichI claim is,

a funnel adapted at one of its extremities to inclose the human mouthand having at its opposite, contracted portion an enlarged, externallythreaded cylindrical extension form ing at its juncture with the funnelan internal shoulder adapted to be laced in opposition to the outer edgeof a te ephone transmitter surrounded by the said extension, and anannulus screwed upon the said extension and having an inturned flangesurrounding the outer surface of the said transmitter.

2. A device of the class named comprising a funnel adapted at one of itsextremities to inclose the human mouth and having at its opposite,contracted portion an enlarged, externally threaded cyllndricalextension form- 1. A device of the class named comprising ing at itsjuncture with the funnel an internal shoulder adapted to engage theoutei edge of a telephone transmitter mouthpiece sur rounded by the saidextension, an elastic Washer upon the said shoulder, an annulus screwedupon the said extension and having an inturned flange and an elasticWasher upon the said flange arranged to frictionally engage the outersurface of the said transmitter mouthpiece.

In testimony whereof I have aflixed my signature in presence of twoWitnesses.

ROBERT H. RALSTON. Witnesses:

G. J. ROLLANDET, K. M. STUMP.

